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  1. 2

    How does gain apply in diff op amp?

    1) Why is it -2 as opposed to +2? I know that, I even said it in my post didn't I... that's not the question. My question is, what is being multiplied by a gain of 2 to get to +0.5V output ??? Or lets look at it this way, if my output is +0.5V from a gain of 2. Then obviously 0.25VDC was...
  2. 2

    How does gain apply in diff op amp?

    Hello, Intuitive deductions in reference to attachment: 1) Initial op amp assumption: Output = 0V Va will sense: va = v1(Ri/Rf+Ri) = 2(10K/30K) = 0.6VDC.... Therefore: 2-0.6 = aprox 1.3VDC Vb will sense: vb = v2(R2/R1+R2) = 5(1.5K/5K) = 1.5VDC Therefore, since the Non inverting input >...
  3. 2

    Inverting input greater than non-inverting input = positive voltage?

    Exactly what I needed to know.... 1.5v on + and 1 v on -. Now it makes sense. thanks guys 24v
  4. 2

    Inverting input greater than non-inverting input = positive voltage?

    Hi John Monks, yes but all maths aside, intuitively, shouldn't the output be 0 v since va will sense 2vdc and vb will sense 1.5vdc??? I mean, if the inverting input is greater than the non inverting input, we should get a negative output right! But since the rails don't have negative but only...
  5. 2

    Inverting input greater than non-inverting input = positive voltage?

    Hello, With the rails at +/- voltages, I was always under the assumption that when the voltage value at the inverting input is greater that the voltage value of the non-inverting input of an opamp, the output would be a negative voltage! OR With the rails, Vcc to positive voltage and...
  6. 2

    AC/DC Power supply with no neutral ???

    Hi Harald Kapp, Yes, this is exactly what I would like to do is perhaps a shunt resistor (High ohms) across the switch just so to power my power supply? Bringing a neutral in the box is not always feasible. So I am snooping around for some alternate solution. I was just wondering if there...
  7. 2

    AC/DC Power supply with no neutral ???

    Hello, I am working on a home automation device where I need low powered electronics within the electrical box of a household switch. Typically we have the line and the neutral wires available in the box. Therefore a small AC/DC power supply would use the existing 120VAC line as the input to a...
  8. 2

    MRF24WB0MA schematic ?

    yes I get your point.... but unfortunately the price can't stay... I will probably sub contract it.... I have no choice unless I start putting mega hours with the risk I will fail.... lol thanks for your feedback
  9. 2

    MRF24WB0MA schematic ?

    yes I skimmed through them but the usage is not the problem.... the price is. I am sure there's not more than 5$ of parts in there and yes, the price difference unfortunately makes a difference for my target price. I was hoping to find some tutorial on how to program the MRF24WB0MA and...
  10. 2

    MRF24WB0MA schematic ?

    Is it possible to find the schematics for such a part: MRF24WB0MA Or is there a replacement circuit that does the same thing? 24V
  11. 2

    MOSFET question?

    thanks Steve! 24v
  12. 2

    MOSFET question?

    I don't understand what you want to get at..... I don't see any such graphs Is it fig5? My point is, if G stays at 3.9Vdc, should IR1 change depending the resistance we put as R1?
  13. 2

    MOSFET question?

    Hello, In attachment below, the amp meter reads 4.78ma. I always figured that when R2 would drop to 20 ohms, the current would increase. But it simply stays the same!!! Why?? Wouldn't lowering the resistance allow more current through the circuit?? In other words, the current is...
  14. 2

    high IR led power?

    you're warning has well been noted! thanks hexreader for your reply! 24v
  15. 2

    high IR led power?

    Hello, I would have a quick question about the TSAL6100 IR LED: http://www.vishay.com/docs/81009/tsal6100.pdf In the absolute maximum ratings section of the data sheet, it says that this led's forwards current is 100ma. But then it also says that the peak forwards current is 200ma...
  16. 2

    Tsop fails on extreme lighting intensities!

    Hi Steve, But does this mean that no sensor in this world can work under the powerful rays of our sun?? r
  17. 2

    Tsop fails on extreme lighting intensities!

    Hi Steve, Ooops, I am sorry.... I should of put the whole part number for the thread's title.... I will make sure of that next time. Well you see, my project may be exposed to direct sunlight. So if it's a sunny day, the tsop4838 may require to still detect objects even though it is exposed...
  18. 2

    Tsop fails on extreme lighting intensities!

    Hello, I am using the Tsop4838 ir sensor and I am able to sense objects at different distances. I then tried to detect those same objects but with a flash light directed right on the tsop sensor. To my dismay, the sensor completely died off producing NO signal at all!!!! Is this...
  19. 2

    max44000

    I think I found my answers here: http://www.eetindia.co.in/STATIC/PDF/201108/EEIOL_2011AUG29_SENS_AN_01.pdf?SOURCES=DOWNLOAD
  20. 2

    max44000

    hello, I have achieved a proximity sensor circuit with the tsop4838 ir sensor. I just ran into this part: http://catalog.gaw.ru/project/download.php?id=39995 Now, I would like to know if anyone used the max44000 part for proximity sensing ???? And can anyone tell me what is the maximum...
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